Wireless and cellular communications handsets are, by their very nature, mobile and used in a variety of locations. These locations include noisy environments such as public gatherings, construction sites, and areas where machinery is operated, such as airports or roadways. Thus, speaker loudness is an important consideration for users and manufacturers of these handsets. This may be particularly true for Push-To-Talk (PTT) type handsets, where incoming sounds may be broadcast either through an earpiece or a loudspeaker. When used in a speakerphone mode, incoming sounds may be directed through the loudspeaker. Thus, a user may position the PTT handset some nominal distance away from their ear during conversations with a remote caller. When used in this manner, the user should be able to distinguish sounds broadcast by the handset from other sounds generated around the user. That is, even with the noisiest of backgrounds, users should be able to recognize and identify communications broadcast by the handset.
It is generally understood that speaker loudness is proportional to driver size. However, as is the case with many consumer electronics, communications handset designs are incorporating more features and more components into smaller packages. Thus, larger speakers or audio drivers may be an impractical solution to generating increased volume. Other factors, including speaker efficiency and the power with which the speaker is driven, may also contribute to higher volume. Unfortunately, these factors may be limited by cost and battery life considerations. Therefore, a passive approach for shaping or increasing handset loudness that does not adversely impact other system characteristics may be a desirable solution.